Lubricating oil testing apparatus



M. CORNELL ET AL 2,027,518

LUBRICATING OIL TESTING APPARATUS Filed Dec. 27, 1932 Jan. 14, 19360 2 Sheets-Sheet 1 /6 /6 INVENTORS Mead Corn// M BY Char/e5 C. Cur/9'5 ZUWZZZJ ATTORNEYS.

Jan. 14, 1936. CORNELL ET AL 2,027,518

LUBRICATING OIL TESTING APPARATUS Filed Dec. 27, 1952 2 Sheets-Sheet 2 g1 FEE- um "mi 7/ /6 /4 'INVENTORS M600 Cor/7e A TTORNEYS.

'- Patented Jan. 14, 1936 g I i UNITEDJSTATES PATENT OFFICE LUBR ICATING OIL TESTING APPARATUS Mead Cornell, San Francisco, and Charles 0.- Curtis, San Leandro, Calif., assignors to Charles C. Broadwater, Oakland, Calif.

Application December 27, 1932, Serial No. 648,842

3 Claims. (CI. 8814) This invention relates generally to methods and The method of our invention can be best unapparatus for determining certain properties or derstood after a detailed description of the appacharacteristics of petroleum products, particularly ratus illustrated in the draW AS illustrated lubricating oils. particularly in Figs. 1, 2, and 5, this apparatus is It is an object of the invention to provide a portable inform and consists of a housing It! 5 method and apparatus of the above character provided with a removable bottom wall H. Parwhich will make it possible by a simple test, to titions l2 and I3 (Fig. 5), arranged within the determine the suitability of used lubricating oils interior of the housing and carried by the bottom for further service. In connection with this obwall, serve to provide a compartment M, for acject, it is possible, by the use of our method and commodating dry cells 16 or other form of electo apparatus, to definitely determine when lubricattric batteries. The remainder of the interior of ing oils used in the crank cases of, automobile mothe housing serves to enclose other parts of the tors or other internal combustion engines, should apparatus, as will be presently explained.

be changed. It is also possible to determine the Formed in the top wall of housing It, there is relative value of different lubricating oil stocks a lateral slot H, which serves to receive what for use in internal combustion engines, and ascan be termed a sampling device 63. Prior to suming that the quality or value of a given lubriexplaining a suitable detailed construction 7 for eating oil is known, we can secure an indication this sampling device, it may be stated that it of the condition of the engine in which the oil serves to retain a sample of oil in such a. manner 20 is being used. that a beam of light may be passed thru the same. 20

- It is a further object of the invention to pro- In order to form a recess or pocket l9 extending vide a method and apparatus of the above chardownwardly from slot H, a pair of vertical partiacter which is applicable for use in ordinary tions 2| and'22 have been illustrated. Flanges automobile filling stations, and which will make 23 formed on partition 22, serve to define the 25 possible a substantially instantaneous indication vertical edges of recess l9. When positioned 25 of the condition of various lubricating oils. within recess E9, the sampling device it may Further objects of the invention will appear rest upon a fixed shelf or stop such as a lug 24. from the following description in' which the pre- In the use of our apparatus a suitable source ferred embodiment of the invention has been set of light is caused to transmit a beam of light forth in detail in conjunction with the accomthru the sampling device l8, and the oil sample 30 pany rawings. retained within the same, and is then caused to Referring to-the drawings! fall upon a photoelectric cell. To-form a suit- Figure l is aplan view, with certain parts broable source of light, we have shown an electric ken away, illustrating one form of our apparatus, lamp globe 26 associated with a suitable reflector which incorporates our method. 21. The periphery of reflector 21 is positioned Fig. 2 is a cross sectional view taken along the within an opening 28 formed in partition 22, so line 2-2 of Fig. 1. that the light will be transmitted directly upon a Fig. 3 is a side elevational view of the sampling portion of the sampling device. To permit redevice utilized as a part of my apparatus, certain moval of reflector 21, thus enabling renewal of parts being in cross section. lamp 26, the base 29 of the reflector is shown re- 40 Fig. 4 is a. cross sectional detail taken along the tained in operating position by a spring strip 3!. line 4-4 of Fig. 3. Likewise fingers 32, fixed to the reflector 27, serve Fig. 5 is a side elevational view of apparatus as to engage partition 22 about the opening 28. Reshown in Fig. 1, in cross section. moval of the reflector together with the lamp 215 Fig. 6 is a fragmentary detail, showing the can be facilitated by providing a removable 45 rheostat utilized in controlling the supply of curclosure 33, in the rear wall of housing 10.

rent to the electric lamp utilized, and also show- Positioned upon the other side of sampling deing certain details of the electric switch used in vice l8, and carried by the partition 2i, there conjunction therewith. is a suitable photoelectric cell 34. An opening Fig. 7 is a circuit diagram showing the manner 36 in partition 2i, exposes that face of the cell 5 in which different parts of my apparatus are 34 which is adapted to receive light rays. electrically connected. In addition to the parts described above, which Fig. 8 is a side elevational view, illustrating the are mounted upon the housing it, we provide a manner in which a p e OI oil is placed in our rheostat 38 and a switch 39, which are incor- Samp devicel porated in an electrical circuit from dry cells it.

and which serve to control the supply of current to the lamp 26. Rheostat 36 may be of conventional type, and is shown with an external control knob 4I. As illustrated it consists of a contact arm 42, operating upon an arcuate coiled resistor 43. Switch 39 can likewise be of conventional construction, and is shown provided with an external operating button 44, which when pressed downwardly serves to close the electrical circuit.

Interposed at some point between the lamp 26, and the electrical element or elements within photoelectric cell 34 which are light sensitive, we provide a proper light filter, having certain predetermined characteristics, as will be presently explained. In the construction shown in Fig. 5

" this light filter has been indicated at 46, and extends over the front face of the photoelectric cell 34. However, it may be otherwise positioned, as for example between the lamp 26 and the sampling device I8, or it may be incorporated as a part of the sampling device. Likewise the filter may consist of a number of elements variously positioned to affect the light rays. 7

To operate in conjunction with the photoelectric cell 34, we provide suitable indicating means, which is preferably electrical in character. Due to the type of photoelectric cell which is preferably employed, this indicating means may consist simply of a microammeter 48, which is mounted within the housing in such a manner that its face is readable thru the housing and wall 49. As evident from Fig. 1, this microarrimeter may be provided with a special graduated scale 5|, to more directly apprise the operator of the character of the oil being tested.

Suitable circuit connection for certain of the parts described above are illustrated in Fig. 7. In this instance battery I6a corresponds to the dry cells I6, and the electricaicircuit 52 which includes this battery is connected to the electric lamp 26, in series with the rheostat'38 andthe electrical switch 39. Meter 46 is directly connected to the terminals of the photoelectric cell 34. Sampling device I8, in its operating position during testing of a sample of oil, is represented by the arrow I 6a.

It may be explained at thispoint that a proper type of photoelectric cell must be utilized, if the indicating means is to consist of a meter directly connectedto the terminals of the same. Photoelectric cells capable of operation in this manner are available on the open market, and are commonly known as photronic photoelectric cells. They are generally constructed of anode and cathode elements, together with a light sensitive material upon the anode which is contacted by the cathode. When light rays fall upon the light sensitive materials, an electrical current is generated, which is capable of operating microammeter or like indicating instrument. As generally constructed such cells are responsive to a wide band of the light spectrum, including that portion of the spectrum corresponding to the natural colors of unused lubricating oil stocks, as

well as to the red end of the spectrum.

A desirable form of sampling device has been illustrated in detail in Figs. 3 and 4. This device consists of a ring shaped body 56, carrying.

, about'15/1000ths of an inch gives good results.

Interposed between the plates 51 there is a cate with the liquid passage 63.

gasket 58 formed of suitable material such as thin sheet metal, and which serves to secure accurate spacing. Gaskets 59 engage the outer peripheral edge portions of plates 51, and the plate assembly, together with the inner and outer gaskets, are clamped together in tight engagement by ring H. To admit liquid into the space between plates 51,'gasket 58 is provided with a pair of divergent slots 62, which communi- Likewise to apply suction to the space between plates 51, to cause inflow of liquid, gasket 58 is shown provided with a slot 64, which communicates with the liquid passage 66.

To provide suction means to be used in filling the sampling device with oil to be tested, we have shown a simple form of suction pump consisting of a barrel 61, the lower end of which is in communication with liquid passage 66. Slidably fitted within barrel 61 there is a piston 68, connected to the inner endofa tubular piston rod 69. Secured to the outer end of tube 69, there is an operating button or knob H, which is provided with an aperture 12 communicating with the interior of tube 69. The passage thru tube 69, also communicates with the space below piston 68.

To facilitate withdrawing of a sample of oil from the crank case of an internal combustion engine, we provide an inlet tube 13, one end of which is provided with a swivel connection 14 to body 56. Thru this swivel connection, tube 13 is in communication with liquid passage 63.

The manner in which the sample device described above is utilized in securing a sample of oil from the crank case of an internal combustion engine is illustrated in Fig. 8. Filling tube 13 is swung downwardly and extended into the oil filling pipe or breather pipe 16, of the engine 11. The operator then places one finger over port 12, to close the same, and then raises button H to create a suction beneath piston 68. Thereupon oil immediately flows upwardly thru tube 13, and into the space between plates 51 thru liquid passage 63 and passages 62. Since passages 62 are divergent, the oil as it enters the space between plates 51 tends to swirl in opposite directions. When the space between plates 51 has been filled, the operator withdraws tube 13; and then by swinging this tube to a vertical position, the sample of oil so obtained is trapped within the device. Likewise with tube 13 in a vertical position, the entire sampling device can now be positioned within recess I6, as illustrated in Figs. 1, 2, and 5. Y

Before explaining the manner in which the apparatus described above is utilized in practice, it is necessary to amplify upon the manner in which the light from lamp 26, is filtered before eifecting an electrical response. Since our apparatus is intended to be used to determine when lubricating oil is unfit for further service, or to determine the extent to which lubricating oil has been broken down thru use, the absorption of light rays by the sample of oil being tested, must be such as to indicate the presence of factors or ingradients in the oil, which appear due to a breakdown of the oil in use. When lubricating oil becomes broken down innse, certain ingredients invariably make their appearance, as for example certain solids such as carbon, which may be of colloidal fineness, and products of decomposition such as petrolic, naphthenic and other acids, and asphaltic residues. However various lubricating of proper characteristics were not utilized with our apparatus, varyingv stocks of new oil, having different color characteristics, would afford decidedly different indications upon the meter 48. A desirable feature of the present invention is that by the use of a color filter of proper characteristics, the effectv of varying naturalcolors of oil is made negligible. This has been made i possible by the discovery that a filter can be provided which matches or is complementary to that band of the light spectrum corresponding to the 7 various colors of the different unused lubricating oil stocks now available on the market.

In practice we utilize a color filter 46 which is absorptive with respect to the violets, blues and the major part of the green rays of the light spectra. It is evident that glass plates 51 of the sampling device, are likewise to a certain extent absorptive with respect to ultra-violet and violet rays. The band of the light spectra over which the filtering is thus effective, is substantially greater than the band represented by the natural colors of various lubricating oil stocks. How

ever such a marginal overlap has been found desirable, to secure the desired result of rendering the apparatus substantially immune from the effect of varying natural colors. The effects secured by filtering the light in the manner just described, can also be explained by stating that the filtering renders the sample of the oil substantially transparent, insofar as various natural colors of different lubricating oil stocks are concerned. In practice good results have been secured by a-filter having a cut-off towards the red end of the spectrum, of about 5800 as expressed in Angstroms units. In this connection we have found that the colors of various unused lubricating oils occupy a band terminating about 4800 as expressed in the same units.

We may now explain the manner in which our apparatus is utilized in practice. Assuming that the apparatus has not been utilized for some time, the operator first assures himself that lamp will burn at a predetermined brilliancy. This is accomplished by pressing button 44, to illuminate lamp 26, while noting the indication of meter 48. The pointer of the meter should stop on a point within that portion of the scale indicated by letter a, which represents new or unused oil. If the pointer does not fall on that point of the scale, then the rheostat knob M is turned to vary' the current supplied to the lamp, until the proper indication is secured. During this time the sampling device is within recess l9, and is empty and clean. The sampling device is now removed, a sample of oil drawn into the same, and the device then reintroduced into recess l9.

The operator then again presses button 44, and' which will directly indicate the condition of the oil with respect to its suitability for further use. For example when the lubricating oil is unfit for further use, due to the presence of ingredients previously referred to in amounts which render the oil unfit for lubricating purposes, the veiling effect or light absorptive properties of the oil sample are such that very little response is secured which accounts for the fact that the meter pointer will lie within the scale portion 17. It 1 has been found that broken down lubricating oil will have a marked veiling effect, even though it has been utilized in conjunction with an oil filter such as is commonly provided in automotive vehicles.

In addition to determining whether or not oil has been so broken down in use as to be unfit for further service, it is apparent that our invention can also be utilized to determine the comparative quality of oils, in terms of permissible useful period of lubrication. Likewise it can be employed to maintain a check upon themechanical condition of an automotive vehicle. In this connection it has been found that when an internal combustion engine is not in good condition,

the crank case lubricating oil will break down more rapidly than if the engine were in better operating condition.

It is evident that between subsequent tests, the

sampling. device should be cleansed by flushing 3 the same with a suitable solvent, such as kerosene. During such flushing, the swirling movement imparted to the liquid entering the space between the glass plates, materially aids in removing adhering oil and solid particles.

It is evident that our invention is susceptible of modification, consistent with the state of the prior art. For example although a color filter is desirable when an ordinary filament type of lamp is utilized as a source of light, and when the photoelectric cell is responsive to a large portion or the light spectrum, it is believed possible to omit a special filter by utilizing a red emitter as a source of light rays, or by employing a photoelectriccell which is' responsive only to the red end of the spectrum, in which event the color filter can be omitted.

We claim:

1. In apparatus for determining the lubricating quality of oil, a casing, a light sensitive cell mounted within the casing, indicating means connected to said cell, a source of light mounted within the casing and spaced with respect to the cell,

a device for retaining a sample of oil, said device including a body provided with a pair of transparent walls spaced a predetermined distance apartwhereby a relatively thin film of oil may be disposed between the same, and also including an inlet tube communicating with the space between the walls and suction means for drawing oil through the tube into the spacebetween the transparent walls and for expelling the same back through the tube, one wall of the casing having an opening therethrough of sufficient. size to permit introduction and removal of said device, and guide means disposed within the casing forming a recess communicating with said opening, the recess being disposed between said cell and the lamp, said guide means serving to position said device with said transparent walls between said cell and said lamp when the device is inserted through said opening, said device when so positioned serving to exclude access of exterior light through said opening whereby only light from the lamp passing through the transparent walls is received by the cell.

2. In apparatus for determining the lubricating quality of oil, a casing, a light sensitive cell mounted within the casing, indicating means associated with the casing and connected to said cell, a source of light likewise mounted within the casing and spaced with respect tothe cell, guide means provided within the casing and serv ing to aflord a recess between the cell and the lamp, one wall of the casing having an opening registering with said recess, and a device for retaining a sample of oil, said device including a body, a pair of transparent walls carried by the body and spaced a predetermined distance apart whereby a relatively thin film of, oil may be disposed between the same, an inlet tube secured to the body and communicating with the space between the walls, and suction means for drawing oil through the tube into the space between the transparent walls and for expelling the same back through the tube under pressure, said tube having a latitude of swinging movement from a filling position in which it extends downwardly from the body, to a position in which it extends upwardly and alongside the body, said recess having a depth less than the length of said tube whereby it accommodates said device only when said tube is swung to a position extending alongside said body.

3. In apparatus for determining the lubricating quality of oil, a casing, a light sensitive cell mounted within the casing, indicating means associated with the casing/and connected to said cell, a source 01 light likewise mounted within the casing and spaced with respect to the cell, 5

guide means provided within the casing and se'rving to afford a downwardly extending recess between the cell and the.lamp, an upper wall of the casing having an opening registering with said recess, and a device for retaining a sample 10 of oil, said device including a body, a pair of transparent walls carried by the body and spaced a predetermined distance apart whereby a relatively thin film of oil may be disposed between the same, an inlet tube secured to the body and 15 communicating with the space between the walls, and suction means for drawing oil through the tube into the space between the transparent walls and for expelling the same back through the tube under pressure, said tube having a latitude 20 of swinging movement from a-illling position in which it extends downwardly from the body, to a position in which it extends upwardly and alongside the body, said recess having a depth less than the length of said tube whereby it ac- 26 commodates said device only when said tube is swung to a position extending alongside said body.v

MEAD CORNELL.

CHARLES C. CURTIS. 

